Shuttle-derived: a done deal

By Jeff Foust on 2005 August 10 at 9:13 pm ET

Space News reported this afternoon that the Defense Department has signed off on a NASA proposal to develop shuttle-derived CEV and heavy-lift launch vehicles. In an August 5 letter to White House officials NASA administrator Michael Griffin and Air Force undersecretary Ronald Sega said that they had agreed that NASA will use shuttle-derived technology to develop a CEV launch vehicle by 2010, followed by a shuttle-derived heavy-lift vehicle. The letter was required by the space transportation policy issued at the beginning of this year, which states that NASA and the DoD would submit a joint recommendation on heavy-lift launch options to the White House.

The announcement is not very surprising: all indications over the last several weeks suggested that NASA was leaning very strongly in the direction of shuttle-derived vehicles (versus EELV-derived alternatives) and that the DoD was willing to agree to such a proposal. In a presentation at last month’s Return to the Moon conference in Las Vegas, Chris Shank, special assistant to the NASA administrator, used slides that featured illustrations of shuttle-derived CEV and heavy-lift vehicles, and later said the DoD was amenable to the concept. Griffin himself, of course, has long advocated shuttle-derived solutions.

The letter includes a couple other decisions about launch vehicle usage:

NASA and the DoD will use EELV-class vehicles “for all intermediate and larger payloads for national security, civil, science, and International Space Station cargo re-supply missions in the 5-20 metric-ton-class to the maximum extent possible.” However, if other competing vehicles become available, they would also be eligible for such launches.

NASA and the Air Force will perform a study on phasing out the medium-class Delta 2. The Air Force is already phasing out the Delta 2 in favor of EELVs, although NASA still uses the Delta 2 for many science missions.

The military would consider using the shuttle-derived heavy-lift vehicle for any potential future applications, but has no interest in using the shuttle-derived CEV vehicle as a backup to the EELV (a concept that had been quietly batted around in recent months as a way to provide assured access while allowing the DoD to downselect to a single EELV family.)

None of these developments are terribly surprising, but the letter—assuming the White House does not object for some reason—clears away any remaining uncertainty about NASA’s future plans.

59 comments to Shuttle-derived: a done deal

That is the first time I’ve heard them say that they will use EELV-class vehicles for ISS re-supply. I really want to know how “if other competing vehicles become available” is determined. IMHO, this is the biggest hole in what Chris and Brant were talking about. If you’re going to have to be substantially there in order to qualify its going to be hard finding investors for such a long development path for an unreliable and unspecified process.

Boeing includes the Delta-IV’s payload to the Space Station orbit on their Web site for potential customers. That suggest to me that they are at least thinking about the idea.

If “Shuttle-derived CSV” means launch on an SRB, I’m very dubious. I suppose they win on simplicity, but what about control? I’m willing to be talked out of this position, but I suspect an SRB CSV would prove every bit as “fragile” as the Shuttle itself.

There is also the fallout. How many of those things can you launch before you dump too much toxic dust on Florida?

Regardless of how many SRB/CSV flights eventually happen, they’ll spew a lot less toxic dust than would have been the case had the Shuttle lived up to its space truck launch-every-two-weeks billing.

Besides, it is Florida. Someone’s liable to collect the stuff and sell it to school kids.

Doesn’t the addition of a second stage to the SRB-derived vehicle give it a degree of control unavailable to a solids-only vehicle? I’m assuming the second stage will handle orbital insertion and the like.

“How many of those things can you launch before you dump too much toxic dust on Florida?”

Good point. No doubt someone will be able to calculate how many people die prematurely each time those SRBs are used. Perhaps somebody already has.

My initial reaction to the SRB launcher was that it would shake the hell out of the CEV systems, causing reliability issues relative to a liquid-fueled launch. Then I worried about the extra risk entailed by having a multi-segment SRB relative to a single segment. And there may be issues with bending stresses too (the same is true for the heavy lift in-line configuration).

The counter-argument is that the shuttle SRB is already man-rated, whereas the EELV engines aren’t. Also there is a great deal of flight experience with those SRBs, whereas the EELVs have only flown a few times.

I can understand why Griffin wants to take this approach given the time and money constraints he has, and for AF’s part Ron Sega (an ex-astronaut himself) either concurred or decided to let NASA do their own thing and stay out of it.

I suppose the idea still doesn’t sit well with me because I think the EELV/CEV combination will ultimately prove to be safer and cheaper than the SRB/CEV combination. Marshall’s numbers put the SRB option as a little cheaper than the EELV; I’m suspicious.

As a stop-gap measure I think SRB/CEV can be justified, but it begs the question what Griffin will do about the longer term. None of the shuttle-derived offerings or anything that Lockheed or Boeing can profitably offer will be cheap enough to sustain the exploration initiative or ulimately achieve its goals.

“Good point. No doubt someone will be able to calculate how many people die prematurely each time those SRBs are used. Perhaps somebody already has.”

I don’t think they’ve been that toxic, studies have been conducted on the subject and although I don’t recall the specifics I don’t think there was a drastic detrimental effect seen from SRB usage. That said I would also prefer to see the SRBs being used less and liquid fueled vehicles more. Not only for environmental reasons, although even for this cold hearty crusty old conservative that IS a concern.

billg: “Doesn’t the addition of a second stage to the SRB-derived vehicle give it a degree of control unavailable to a solids-only vehicle? I’m assuming the second stage will handle orbital insertion and the like.”

That’s true, and the fins on the SRB are supposed to give it a bit of roll control also. And the SRB knozzle does have a limited gimble capacity.

I’m sure the SRB is more than adequate to do the job of sending the CEV into orbit. Guidance is as old as rocketry itself, and that is something the engineers can handle. Indeed, the SRB has proven itself 224 times in flight, with several early units showing O-ring burn through and one causing a catastrophic failure. In all the bad cases, an escape tower would have pulled a CEV away. In the catastrophic failure, it was the SRB’s unintentional exhaust interaction with the ET that caused the destruction of the vehicle. No such configuration will exist with the new system.

As for EELV addressing ISS needs – it can. So can Proton, Soyuz, and Ariane 5. I see no show-stopper. Payloads can be adjusted, fuel mass shifted, and new guidance configured. It can be done – and should be.

The SRB may not be “human rated” per se, but the STS is human-rated by definition. It has also proven itself to be a safe method of sending humans on their way to space. I would certainly sit on top of an SRB as an astronaut in a CEV, and would feel especially comfortable knowng I had the option of using an escape tower. On the Shuttle, once the SRBs are lit, all you could do was ride it out. Now that IS scary.

The Delta 4 and Atlas 5 are not human-rated, and the cost to get them there was expected to be large. This is part of the reason why using them for CEV was not favored.

Rand on man-rating: “What’s your basis for that statement? I’m not aware that it is.”

OK, I see what you’re getting at. The SRB is not man-rated for this task, you are absolutely right.

So correct me if I’m wrong: The bulk of the expense, time and paperwork involved in the man-rating process is certifying the engines. The key question would therefore be does NASA have to re-certify the SRB engines as part of the man-rating process? If so, that changes everything.

Finally, just as a point of interest, here’s a vintage posting in which Henry Spencer explains emergency thrust termination with the shuttle SRBs:

During a stick CEV launch, an O-ring failure (as with Challenger) would not have caused loss of crew. In over 200 launches of the SRB there have been NO failures that would have caused loss of crew for a stick CEV.

If the fuel grain is formulated properly, a solid rocket cannot explode. Small explosives to open holes in the rocket motor casing leads to thrust termination accompanied by CEV escape tower activation.

= = =

I still favor the t/Space air launch system and I do believe Griffin will eagerly buy t/Space for ISS crew transfer if/when Gump & Company get the thing flying.

It’s not clear why the dust emitted by the solids is especially problematic. Aluminum oxide isn’t particularly toxic (or else we’d better take Maalox off the shelves), and the acid chlorides are going to be rapidly neutralized anyway (Florida bedrock is mostly limestone, right?) It’s not as if the SRB fuel is loaded with toxic heavy metals.

The bulk of the expense, time and paperwork involved in the man-rating process is certifying the engines.

I don’t even know what that means. The only thing that I can think of that one would do to “certify” those engines for “human rating” would be to establish that they had an adequate failure onset detection (FOSD) system that would provide sufficient warning to pull the lanyard on the launch abort system. While the SSMEs have such a system (which may be why NASA prefers them to the 68s), it’s not at all clear to me how one would even have such a system on a solid in general, let alone an SRB, (or some new version of it based on the ASRM).

Again, this is why I wish that people would stop using the phrase (a wish that, I believe, Mike Griffin has shared in the past). Very few people who do have any idea what it really means. It will recede into history once we start building reusable space transports the way God intended, instead of continuing to put people up in capsules on high-grade munitions.

The bulk of the expense, time and paperwork involved in the man-rating process is certifying the engines.

I don’t even know what that means. The only thing that I can think of that one would do to “certify” those engines for “human rating” would be to establish that they had an adequate failure onset detection (FOSD) system that would provide sufficient warning to pull the lanyard on the launch abort system. While the SSMEs have such a system (which may be why NASA prefers them to the 68s), it’s not at all clear to me how one would even have such a system on a solid in general, let alone an SRB, (or some new version of it based on the ASRM).

Again, this is why I wish that people would stop using the phrase (a wish that, I believe, Mike Griffin has shared in the past). Very few people who do have any idea what it really means. It will recede into history once we start building reusable space transports the way God intended, instead of continuing to put people up in capsules on high-grade munitions.

The phrase “man rated” has a certain $ring$ to it, doesn’t it? I’ve heard there are studies suggesting ammonium perchlorate is a problem with respect to solid propellant manufacture due to the potential for ground water contamination. It’s hard to get the straight scoop on things like that now with everyone wanting to sue everyone else.

“Human rated,” or the more archaic “man-rated,” aren’t certifications or official blessings. They are simply industry terms to indicated that a vehicle has qualified itself to carry humans, and this is historically arrived at on the first flight with humans aboard.

It does mean a significant amount, because one’s impression of a vehicle’s reliability shifts when considering robotic payloads versus astronauts.

The real question is this: have we become too risk averse, producing thresholds that simply stifle progress? My answer: yes.

One article I’ve read about shuttle derived launchers said 5 billion dollars would be spent to develop the SRB derived CEV launch vehicle, and another 5 billion to develop the SDHLV. Doesn’t sound like “safe, simple, soon” to me. Sounds more like the development cost of the CEV launcher will subsidize the development cost of the heavy lift vehicle.

NASA plans maximum use of common components for both launch vehicles. Not only will they share the SRB they are going to share the LH2/LOX final stage as well. So this decision is not really about low cost for the CEV launcher, it’s really about finagling the heavy lift vehicle. If the true costs of heavy lift vehicle development were on the table it would be a lot harder for NASA to sell the idea to Congress.

“Man rated” is archaic? Are you calling me archaic? Darn, the truth hurts. Well, in this case, just kinda stings a little.

NASA doesn’t have a man rating standard, like the FAA’s FAR for aircraft, but there are some features most of these vehicles have. I believe there are generally some attempts to design redundant load paths in structure. There are some stringent requirements for pressure vessels regarding proof testing and factors of safety. In liquid fuel rockets, they generally prefer multiple engine configurations so the vehicle can continue with one engine out. It is debatable, however, as to whether or not multiple engines actually enhance safety.

The main impact of man rating is usually seen in the avionics system design. Typically the avionics are designed to be single failure tolerant for mission success and dual failure tolerant for safety. That usually means two parallel avionics systems with triple inhibits to prevent inadvertent activation of anything that might hurt an astronaut. Rockets also generally use lots of pyrotechnically activated mechanisms. These are generally mission critical and therefore use redundant squibs or detonating cords.

There are also some extensive requirements for testing and documentation. Qualification and acceptance testing is done on everything, much as it is with aircraft. Also a parts pedigree is maintained, which is supposed to prove that all parts are appropriately manufactured and screened and can be tracked to each vehicle. This way, if a manufacturing lot of parts is found to be defective, the effected vehicles and systems can be identified and the offending parts removed. That system is probably used for all rockets or missiles these days. One of the biggest costs of man rating is all of the meetings and reviews NASA requires to make sure all of the requirements for all this stuff have been met.

I don’t think this approach to man rating is inherently useless. Many of the same techniques are used in the design of aircraft structures, pressure vessels, and avionics systems. What makes it gilding, however, is going to all the trouble to put these highly reliable systems on a rocket that itself either blows up or burns up every 50 missions. When you actually do the calculations, you find that the safety or reliability gains made by man rating are insignificant, especially when compared to the fantastic costs. On the up side, all of these requirements ensure that plenty of people have jobs, with large salaries paid by you, the taxpayer.

I fear this “done deal” will have negative repercussions to the overall space program for many, many years.
The technical hurdles the “stick” must overcome is cause for concern. One must remember this proposed SDV does not utilize the same SRBs that enjoy good demonstrated reliability. The proposed stick will use a differently throated, 5-segment configuration with a proposed second stage engine based upon the J2. The stick’s solid first stage is unproven and the J2 has not been in production since the 70s. While the proponents may claim this LV to be “shuttle derived”, it is a tenuous claim at best. This is a new vehicle.
Another thing that concerns me is the development (never mind the recurring) costs of this launch vehicle. With the development costs estimated to be >$5B, I find this extremely expensive for a launch vehicle that is expected to launch 4-5 times per year. I’ll let the readers do the math on how many EELVs can be launched for $5B (and please don’t use the figures from MSFC. Those cost numbers are so inflated they are laughable).

The human-in-the-loop requirements look like they were written by the astronaut corps. Quite what use taking manual control of an oversized firework would do is beyond me… If they really must have control of the vehicle, surely that rules out SRBs altogether?

I’ve just found Griffin’s comments on man-rating in none other than the space review:

“Griffin noted that the term “man rating” dated back to efforts in the 1950s and 1960s to modify ICBMs to carry capsules. “This involved a number of factors such as pogo suppression, structural stiffening, and other details not particularly germane to today’s expendable vehicles. The concept of ‘man rating’ in this sense is, I believe, no longer very relevant.”

He argued that EELVs and other expendable vehicles are already called upon to launch high-value unmanned payloads. “What, precisely, are the precautions that we would take to safeguard a human crew that we would deliberately omit when launching, say, a billion-dollar Mars Exploration Rover (MER) mission?” he asked. “The answer is, of course, ‘none’. While we appropriately value human life very highly, the investment we make in most unmanned missions is quite sufficient to capture our full attention.”

The Atlas 5 and Delta 4 EELVs, he noted, have a specified design reliability of 98 percent, in line with experience with the premier expendable vehicles to date. If such a vehicle was used to launch a crewed spacecraft equipped with an escape system of just 90 percent reliability, he noted, the combined system would have a 1-in-500 chance of a fatal accident, “substantially better than for the Shuttle.””

Interesting, things haven’t changed much. That document seems to be written from a pilot/vehicle interface (PVI) point of view. There are a lot of requirements (shall statements) hidden in the referenced documents. NASA-STD-3000 alone is huge. That document itself is not exactly a Reader’s Digest summary of manned space flight, is it?

I suppose a pilot could steer a rocket on the way up. Most of them are stable, or close enough to stable not to need a computer like an X-29, but it still seems like a scary prospect. It might not be such a bad feature to have on a solid, since there’s no turning them off.

There is a difference between development costs and launch costs. Development cost is a one time expense required to design flight structure, hardware, software, as well as develop and build the tooling; then test and trouble shoot the vehicle. It doesn’t include the actual cost of the materials and labor that go into the vehicle itself, which is the cost that’s repeated each time one is built, or flown in the case of expendable components.

“Griffin noted that the term “man rating” dated back to efforts in the 1950s and 1960s to modify ICBMs to carry capsules. “This involved a number of factors such as pogo suppression, structural stiffening, and other details not particularly germane to today’s expendable vehicles. The concept of ‘man rating’ in this sense is, I believe, no longer very relevant.”

He argued that EELVs and other expendable vehicles are already called upon to launch high-value unmanned payloads. “What, precisely, are the precautions that we would take to safeguard a human crew that we would deliberately omit when launching, say, a billion-dollar Mars Exploration Rover (MER) mission?” he asked. “The answer is, of course, ‘none’. While we appropriately value human life very highly, the investment we make in most unmanned missions is quite sufficient to capture our full attention.”

Ah, a man after my own heart (at least on that subject, if not on heavy lift). And what he says about ELVs goes more than double for reusable vehicles. Unreliable vehicles are very expensive, and whether or not they carry people is completely irrelevant.

Thanks for the link, Kevin. It looks like from what Griffin said he would be in favor of getting rid of the two fault tolerance requirement for safety in the avionics system design. This could actually drive costs down significantly by reducing system complexity and the number of components required.

Also I think there is an unquantifiable aspect that would improve, which is attitude related. Right now, the people who work on these avionics systems see them as being way over-designed, which results in some lax attitudes toward safety. You almost have to prove to them something is wrong before they’ll do anything about it. If NASA would invest more money in the real drivers of safety and reliability, such as a reliable escape system, more reliable engines, and more reliable reentry systems, then you’d start to see the needle move. There would be an across the board improvement in motivation.

Griffin: “The concept of ‘man rating’ in this sense is, I believe, no longer very relevant.”

Note that Griffin did not say the term was not relevant, just no longer “very” relevant.

Back in the day when Atlas launchers blew up with regularity man rating had more meaning than it does today. There is still some difference in systems between launchers used for launching humans and those that are not (as defined above by Dfens) but those differences are not as great as they once were. I think “man rated” (or human rated for the PC crowd) is still an accurate term to define those differences, even though it doesn’t mean as much as it once did.

I don’t quite understand this bizarre bias against the concept of “man rating” a rocket. It strikes me as a typical chip-on-the-shoulder alt-space complaint that fails to understand actual launch operations.

Suppose you have a vehicle that is 100% reliable. Guaranteed. That makes it “man-rated,” right?

No, actually it doesn’t. What if that totally reliable vehicle accelerates at 9 gees, or vibrates substantially and would injure or kill the crew on ascent? Either you alter those characteristics–and “man-rate” it–or you cannot use it. “Man-rating” a vehicle also means things like instrumenting it so that you can feed that data to the launch escape system for the crew. Or eliminating failure modes that are acceptable for robots but would kill the crew.

And some vehicles have characteristics that are not crew friendly even if the vehicle is highly reliable. For instance, the Delta IV actually catches on fire during launch. Imagine a main engine shutdown on the pad and a vehicle fire. This limits the ability to have the crew do a pad egress. They would step out of their spacecraft into a fuel rich atmosphere and a burning vehicle.

So these claims that “man-rating” a vehicle are illusory are not an example of clear-headed thinking.

Suppose you have a vehicle that is 100% reliable. Guaranteed. That makes it “man-rated,” right?

No. As you point out, reliability is only one part of the equation. Nonetheless, much of the talk about human rating is based on a foundation of ignorance. That’s what I object to (by the way, humans can take 9 gees in a gee suit, and anything that vibrates so much that it would kill or injure humans is in fact unlikely to be a “hundred percent reliable,” guaranteed or otherwise, or friendly to the electronics of payloads).

Your comments in the past have been rather absolutist–essentially claiming that there is no such thing as “man-rating,” when that is clearly wrong. So to refute your absolutist claims, I picked extreme examples.

“and anything that vibrates so much that it would kill or injure humans is in fact unlikely to be a “hundred percent reliable,””

As for the vibration issue, I would note that solid-propellant ICBMs actually have significant vibration during launch. This presents little problem for robust electronics and a bomb. But it has been one thing that limits their attractiveness for scientific or other satellites.

Your comments in the past have been rather absolutist–essentially claiming that there is no such thing as “man-rating,” when that is clearly wrong.

I’ve never said there’s no such thing. I’ve said (like Dr. Griffin) that it’s an archaic and unuseful concept from the sixties that we’ve come to outgrow, and should have little applicability to modern vehicles, but many don’t realize this, or even realize what it means. It’s just a buzz phrase that many people throw around to make it sound like they know what they’re talking about.

So Rand, since “man rated / man rating” is so archaic, what phrase would you suggest we now use in describing the differences in manned/unmanned launchers and the process by which those differences come about?

…since “man rated / man rating” is so archaic, what phrase would you suggest we now use in describing the differences in manned/unmanned launchers and the process by which those differences come about?

That’s a good question. Ideally, we’d evolve to the same model as the aircraft industry (in which such a term doesn’t exist, because the notion of a pilotless aircraft has been an oxymoron, though that’s changing with UAVs).

I think what really bothers me is this weird notion that the lives of astronauts are somehow worth more than a billion-dollar satellite. It’s not rational–it’s entirely emotional. In the current state of things, every time we launch almost anything, there are hundreds of millions of dollars at stake. If that’s not enough to motivate people to spend enough money on reliability, then we’ve gone insane on an industry level, and as we’ve seen with the Shuttle, spending more because there are people on board is largely a waste of money, because it doesn’t seem to buy us much.

Ignoring the valid issues that William Berger brought up (which are not the ones that most people associate with the concept of “human rating,”) I’d like to just see people talk about reliability. Lord knows that this industry needs it very badly.

Jeff (and then Mike Mealing) raise the issue of whether or not cargo would be delivered to the International Space Station using EELVs and/or new commercial systems.

As the person quoted at the end of Jeff’s article about Chris Shank’s and Brant Sponberg’s speeches… I’d like to clarify a few issues.

First, the U.S. Space Transportation Policy states that all unmanned U.S. gov’t launches in the 5-20 MT class will be done on EELVs, but that new systems in that class will be utilized as they become available.

In that sense, the letter from Griffin and Sega to the White House is simply reflective of policy: the default way to launch unmanned payloads is EELV, and therefore the deault way to launch cargo to the vicinity of ISS is probably EELV.

That does not mean that private companies cannot bid much cheaper/better launch systems as part of the forthcoming ISS cargo service acquisition, which was forecast by Brant Sponberg at RTM-6. But you will also notice that there were other launch vehicle opportunities besides ISS cargo.

But the procurement method Brant talked about for ISS cargo delivery was fixed price commercial services, not development contracts or prizes for new launch vehicles. If launcher companies like SpaceX, Kistler, and AirLaunch can’t beat full-costed (but not amortized development) EELV launches on price performance, then… why do we call ourselves the Cheap Access to Space industry?

Second, the real challenge isn’t competition from EELV but from Shuttle in the near-term and from uncrewed CEV and Single Stick in the long run. The shuttle is starting to age a little less gracefully than it used to, but the key issue is whether NASA follows through and starts buying commercial cargo services this fall.

Then, after Shuttle is retired, there will be pressure to use funds for buying commercial cargo services and enable entrepreneurial crewt to orbit and use those as billpayers for CEV or the Single Stick. After all, CEV and CLV will have significant fixed costs, and therefore some in NASA and industry will argue that it makes sense to use CEV to deliver crew and cargo to ISS. Of course, Shank pointed out at RTM6 that if NASA has to fall back on this option, crewed missions to the Moon slip to the right beyond 2020.

Therefore it’s not affordable/sustainable to use those expensive systems for ISS crew and cargo transfer. Butit wouldn’t be the first time that critical goals of a space policy were sacrificed on the altar of contractor profit or political pork.

Third, there is an issue with regards to “last mile to ISS”. Various different approaches have been proposed, from launcher-specific transfer vehicles (eg. Kistler’s 2nd stage) to the ATV (which ESA will launch on the Ariane 5 but Space News says Lockmart could launch on the Atlas V) to other concepts from companies like Spacehab, CSI, etc… The last mile is a challenge, but it’s probably a good sign that Griffin, in his June 21st speech to the Space Transportation Association, specifically suggested that NASA would buy commercial “middleman” or last mile services.

So, bottom line: EELVs are an option, not a mandate. CLV is a threat. Last mile is a barrier but also an opportunity for innovative teaming.

DISCLOSURE: I may work for one or more companies mentioned above, but the opinions I am stating are only my own, based on my knowledge and interpretations of where Griffin & Co are going here.

Mr. Simberg wrote:
“I’ve never said there’s no such thing.” [as “man-rating”]

You wrote: “[n]or that the very concept of man rating has any utility.”

Sounds like a pretty absolutist statement that there is no utility to the concept of “man-rating” a launch vehicle. Is there much difference between “it is a useless distinction between the two” and “it doesn’t exist as a distinction”? I don’t think so. I think that your blanket statements dismiss a very real issue.

Simply put, although high reliability is important for BOTH manned and unmanned vehicles, there are clearly a set of additional criteria that are applied to manned vehicles. Although there is no set list of what these criteria are, it boils down to a basic requirement that failure of the launch vehicle should not necessarily lead to death of the crew. Systems required to achieve this are “man-rating” systems. And sometimes it may not be possible to convert a launch vehicle into a “man-rated” vehicle because its inherent characteristics (such as types of failure modes) make it hard to incorporate safety systems or achieve a high level of crew survivability.

Although you claim that passenger jets are not “man-rated” but achieve safety through high reliability, this is an overly simplistic and limited statement. Passenger jets achieve safety with more than simple high reliability. They have emergency exits, emergency lighting, fire retardent materials, none of which really contribute to the reliability of the vehicle, but do contribute to the survivability of the passengers. And most of these are required by civil aviation authorities. In other words, outside authorities require safety systems for passenger jets–just as government authorities require safety systems for vehicles designed to launch humans into space.

Furthermore, if you expand the scope of your analogy a little to include military aircraft, you can see that they also carry systems that help insure survivability of the crew if the basic flight reliability of the aircraft fails–and that government officials require these systems. Ejection seats are the obvious example. But military jets also have many monitoring and warning systems to inform the pilot on the state of his aircraft–precisely to enable him to abandon it once it fails. The F/A-22 is designed to be the most “survivable” fighter aircraft ever built, largely because it is supposed to be invisible to the enemy. And yet it still is equipped with an ejection seat and engine fire warning lights.

So different forms of “man-rating” exist for aircraft. Nobody has applied a specific term to them, but the people who design and build aircraft know that these kinds of requirements exist. Commercial aircraft manufacturers, for instance, know that there is a body of regulations that they have to apply to passenger aircraft that they do not have to apply to transport aircraft. They refer to these regulations not by the term “man-rating” but instead call them by their government regulation number. They know that there are certain requirements expected for military aircraft (e.g. ejection seats) that are not expected for other aircraft. And they know that if they do not include an ejection seat in a fighter aircraft, they will not only not win a USAF contract, they will probably be declared crazy by the pilot mafia.

You have claimed that the shuttle is not “man-rated,” but that is also false. There are systems incorporated into the shuttle that would not be there if the vehicle had no crew. For instance, the flight termination system is designed in a different way than it would be for an unmanned vehicle.

“I think what really bothers me is this weird notion that the lives of astronauts are somehow worth more than a billion-dollar satellite.”

But this statement ignores the entire context of human spaceflight. Right now there is no rational, logical reason to launch humans into space that justifies their cost. This is not true for satellites. So, once you accept that humans are launched into space for reasons that are essentially emotional (what is national prestige other than emotion expressed through geopolitics?), you should accept that the loss of astronauts will be an emotional event. The government is not run by Mr. Spock.

And you can complain about it all that you want, but the people who pay the bills (the Congress, spending taxpayer money), do not agree with you. They consider human life to be worth added cost.

> Ejection seats are the obvious example. But military jets also have many monitoring and warning systems
> to inform the pilot on the state of his aircraft–precisely to enable him to abandon it once it fails.

No, they are to enable the pilot to take corrective action. That’s what pilots DO.

Pilots DO NOT eject at the first sign of trouble. That’s a misconception. No pilot wants to eject. The phrase used is “attemted suicide to avoid certain death.” Even “successful” ejections often leave pilots with long-term medical problems.

> The F/A-22 is designed to be the most “survivable” fighter aircraft ever built, largely because it is
> supposed to be invisible to the enemy. And yet it still is equipped with an ejection seat and
> engine fire warning lights.

You just shot down your own argument: F-22 designers still thought about safety. In aviation, ejection is a last resort, not a first resort. Pilots don’t eject the first time an engine starts running rough, and designers don’t think they can forget about safety just because the plane’s going to have an ejection seat. That nonsense is limited to the missile community.

> They refer to these regulations not by the term “man-rating” but instead call them by their government
> regulation number. They know that there are certain requirements expected for military aircraft
> (e.g. ejection seats) that are not expected for other aircraft.

You need to look at the reasons for those regulations. The USAf does not design fighters with a >1% peacetime loss rate, then tell pilots they are “safe” because they have ejection seats. There’s a big difference between having an ejection seat in case you’re hit by an enemy missile and having an ejection seat because someone couldn’t be troubled to design an engine that wouldn’t blow up on takeoff.

> Right now there is no rational, logical reason to launch humans into space that justifies
> their cost. This is not true for satellites.

Hogwash.

And if you really believe robots are superior to men, you shouldn’t be so eager to blow your robots up.

> They consider human life to be worth added cost.

There’s a hidden assumption in your argument. You haven’t shown that the added cost saves lives. A comparison of the X-15 program with the Atlas A showed that resuable vehicles are cheaper to develop in part because they have lower failure rates.

> There is a difference between development costs and launch costs. Development cost is a one time
> expense required to design flight structure, hardware, software, as well as develop and build the tooling;
> then test and trouble shoot the vehicle. It doesn’t include the actual cost of the materials and labor
> that go into the vehicle itself, which is the cost that’s repeated each time one is built, or flown in the
> case of expendable components.

Development does not end with the drawing of the blueprints. A big part of development is testing. (“To develop a rocket, you have to launch a rocket.”) It *does* include the cost of materials and labor that go into the rocket, and for an expendable rocket, it will include them many times over.

Nor is development really a one-time expense. Most vehicles have sustaining engineering efforts that go on for years.

Sorry, William, but now you’re changing the meaning of words. “Man rated” is a very specific term of art in the space industry, and is a different thing than commercial aircraft certification. JSC has a guide describing what it entails. Shuttle does not meet it. And all this talk about “man rating” boosters ignores the substantive issues of reliability requirements, regardless of the nature of the payload.

Of course we should design vehicles with humans in mind, if they’re going to carry humans, and we should design them to be reasonably (though not unreasonably in terms of cost) safe. But the traditional notions of man rating are not necessarily the best path to that goal, and Dr. Griffin seems to agree.

Does a twenty-plus ton lunar payload include the mass of the third stage booster that will be needed to achieve escape velcity?

Unless the second and third stages of this proposed lunar Crew Exploration Vehicle stack have surprisingly high performance, I think it can be rigorously shown that the existing four segment Solid Rocket Booster will not do the job.

Build a five segment version of the SRB? A five segment SRB is neither off the self, nor “proven,” nor “man rated.”

Jim,
Thanks for that clarification, but my concern still stands: given that the stick, CLV, CEV, and EELVs are all contendors that have a legislated ‘in’ for ISS resupply as well as other uses, how are each of the constituencies behind those systems going to pervert the NASA process of determining if/when a new commercial provider has ‘proven’ they can compete? At the STA breakfast Mike said he was going to pick a ‘leader’ and then fund them just enough to “keep them pink”. What happens if the EELV lobbyists use political pressure to influence how that ‘leader’ is picked?

Don’t get me wrong, this is a fairly minor bit of bitching on my part. I’m still very much on board with what Brant and Chris said, but the time period between ‘idea/team/funding’ and ‘first NASA contract’ has all been just hand waiving. Is anyone at NASA working on making that process transparent and predictable?

[ What happens if the EELV lobbyists use political pressure to influence how that ‘leader’ is picked? ]

You expect lobbyists to refrain from lobbying?

One rather cynical reading of this agreement is that the Defense Dept. and the EELV venders are expecting Dr. Griffin’s Thoikol-centric designs to fizzle out, and then DOD/EELV can step in and pick up the funding …

… without being blamed for aborting the beautiful new Solid Rocket Booster baby.

Ultimately I suppose it doesn’t really matter whether you call it “man rating” or “soap on a rope” there is a certification process, which is not well defined or documented, that applies to manned launch vehicles. This process is more rigorous and detail oriented than the process for unmanned vehicles. It borrows heavily from the FAA certification process for aircraft, and includes some features that were born of the Apollo program.

The problem is, the process doesn’t make sense. I ask again, why put an avionics system on a rocket that has a safety failure rate of 1 x 10-9, when the rocket fails catastrophically at a rate of 1 x 10-2? Here again, NASA weighs the contractor down with massive numbers of requirements, hires boat loads of people to monitor their performance with respect to the requirements, has hundreds, if not thousands of safety reviews to make sure all of the requirements are met, and yet ends up with a vehicle that still has a 1 x 10-2 failure rate.

Wouldn’t it be better if they provided the contractor with a top level failure rate they thought acceptable. For instance, Griffin has stated his goal for the next vehicle is a failure rate of 1 x 10-3. Make that a requirement for the next vehicle, provide a financial incentive to meet it (as well as a disincentive not to), and let the contractor allocate it to the various subsystems in a way that makes cost effective sense.

And while they were at doing things that make sense (for a change) they could also stop mandating that reliability and safety engineers work for the program office, and provide them with the autonomy they once had to make a difference on these vehicles. Everyone always has all of these theories on how to make space travel safer and more reliable, but they never seem to include pulling the disciplines that obviously should be working these issues back from the brink of total irrelevance.

This seems like some pretty obvious stuff, doesn’t it? Remember when the term “rocket scientist” implied someone had a bit firmer grasp of the obvious?

> I suppose it doesn’t really matter whether you call it “man rating” or “soap on a rope” there is a
> certification process, which is not well defined or documented, that applies to manned launch
> vehicles.

The process is very well documented.

> It borrows heavily from the FAA certification process for aircraft

It has nothing to do with aircraft certification, which is based on hundreds of hours of flight testing, with hundreds of takeoffs and landings. Such a process has never been applied to ELVs and, for obvious reasons, it never will.

> why put an avionics system on a rocket that has a safety failure rate of 1 x 10-9, when the
> rocket fails catastrophically at a rate of 1 x 10-2?

For one thing, component failure rates are cumulative. To make a rocket 99% reliable, you may need parts that are more than 99% reliable.

More to the point, why design a rocket to fail catastrophically at a rate of 1 x 10-2, when it would probably be cheaper (and certainly more useful) to design a rocket that’s reliable?

> For instance, Griffin has stated his goal for the next vehicle is a failure rate of 1 x 10-3. Make that
> a requirement for the next vehicle

In 40 years, no ELV has come close to meeting that requirement. What’s the point of specifying an ELV then specifying a “requirement” that no ELV can possibly meet? Even if an ELV could meet that goal, how would you prove it, with a rocket that might fly a few dozen times in a decade, at best?

> There are also some extensive requirements for testing and documentation. Qualification and
> acceptance testing is done on everything, much as it is with aircraft.

Acceptance testing is not just kicking the tires on an aircraft. Every plane that comes out of the factory completes a series of acceptance test flights. Such tests are never done on ELVs, for obvious reasons. Each ELV flies only once; it cannot do acceptance test flights before delivery to the customer.

I wrote:
“But military jets also have many monitoring and warning systems to inform the pilot on the state of his aircraft–precisely to enable him to abandon it once it fails.”

Wright wrote:
“No, they are to enable the pilot to take corrective action. That’s what pilots DO.”

I should have clarified a bit more. Some of the warning lights in military aircraft enable the pilot to take no corrective action. They only provide an indication of how crippled his aircraft is. In other words, the aircraft is equipped with sensors and indicators to enable him to decide when he must eject.

Unfortunately, I detect too much confrontational attitude (and just plain anger) in many of Mr. Wright’s posts. So I do not see any point in engaging him further. Life is too short to argue with people who take their frustrations out on the internet.